1. Field of the Invention
The invention relates to an input device and a method for handwritten input of characters on a user interface.
2. Related Art
Known input devices for handwritten input of characters comprise, for example, touchpads and touchscreens as the user interface. These known input devices detect the movement of an input pen or a user finger on the user interface, and convert the detected movement into an input pattern. The input pattern is compared with a stored character set, and if there is a sufficient match between the input pattern and one of the characters in the character set, this character is selected. WO 2009/040322 A1 discloses the principle of such input devices and the use thereof in motor vehicles.
When the input device is used for handwritten input of characters onto a user interface in a motor vehicle, the user interface is normally not in the primary field of view of the driver and must therefore mostly be operated “blind”. Input problems can arise here if the driver comes up against the edge of the user interface with the input pen or his finger when writing a character even though the input of the character is not yet complete. This problem is primarily caused by the fact that the driver does not have appropriate feedback about the position of the input pen or finger on the user interface because he is normally looking not at the user interface but at the road activity.
WO 03/027822 A2 discloses a further input device for handwritten input of characters onto a user interface.
This operating device generates and outputs, while a character is being input, an acoustic signal that is dependent on the input pen used.